Fig. 4. Multifocal optical systems in combination with circular pupils are present in the beauty snake (Orthriophis taeniurus friesi; A,B) and house mouse (Mus musculus; C,D). The partially constricted pupil of the house mouse was visualized using infrared light because in the visual range the iris was as black as the pupil and the flashlight of the camera did not illuminate the eye at close range. Scale bars are 2 mm.